Reliability and validity of the Netherlands Triage Standard in emergency care settings: a case scenario study.

Background: The Netherlands Triage Standard (NTS) is a triage system that can be used by different types of emergency care organisations. Our objective was to determine the interrater reliability and construct validity of the NTS when applied to self-presenting patients.

Methods: We performed a cross-sectional case scenario study consisting of two parts: (1) paediatric triage in January-February 2019 and (2) adult triage in October-November 2020. In each part, we invited nurse triagists from three general practitioner cooperatives, three ambulance dispatching centres and three hospital emergency departments in the Netherlands to participate. We used 40 case scenarios involving paediatric patients and 41 involving adult patients who could self-present to any emergency care organisation. In advance, an expert panel determined the urgency (six levels) of the case scenarios (reference standard). The main outcome for reliability was the intraclass correlation coefficient (ICC) for urgency level. The main outcomes for validity were degree of agreement with the reference standard, for urgency level, and sensitivity and specificity for high versus low urgency. We used descriptive statistics and logistic multilevel modelling with both case and triagist as random effects.

Results: 218 out of 240 invited triagists participated. The ICC among all triagists was 0.73 for paediatric cases and 0.88 for adult cases and was highest in general practitioner cooperatives. For paediatric cases, there was 62.3% agreement with the reference standard about urgency, 17.4% underestimation and 20.2% overestimation. The sensitivity of the NTS for identifying highly urgent paediatric cases was 85.2%; the specificity was 89.7%. For adult cases, there was 68.3% agreement, 13.7% underestimation and 18.0% overestimation. The sensitivity of triage for high urgency in adults was 94.5% and the specificity 83.3%.

Conclusion: NTS appears to have good reliability and construct validity for estimating the urgency of health complaints of non-referred patients presenting themselves in emergency care.